Research On Comprehensive Accessibility Of Urban Track Sites Based On Internal And External Relations

Rail transit is an effective way to solve urbanization problems such as traffic congestion and environmental pollution.However,rail transit can only provide "station-to-station" services,and cannot provide "door-to-door" services.It must coordinate and cooperate with various modes of transportation.The track site has gradually become an important node connecting the interior of rail transit and the living space outside the city.As an effective means widely used to evaluate the efficiency of transportation infrastructure,accessibility can not only consider the driving effect of the built environment around the track site on the efficiency of the site,but also improve the efficiency of the railway station from the operational perspective of the online network.Therefore,the optimization of the accessibility of the track site plays an important role in the coordinated development of urban rail transit.On the basis of the definition of accessibility of the track sites,on the one hand,based on the travel behavior of rail transit travellers,consider the personal characteristics,travel characteristics and mode attributes of rail transit travelers,the radiation range model of the rail transit station for each type of station was constructed.According to the result of the model,combined with the statistical analysis function of GIS software,the external accessibility model of the track site based on the radiation range is established.On the other hand,starting from the perspective of the operation of the track site,the rail transit time network and topology network are constructed from the two perspectives of time and topology,and the weighted average travel time was usedto establish the internal accessibility model.Finally,according to the internal and external accessibility models,combined with the entropy weight method,the track site accessibility model based on internal and external linkages was established.Taking Xi'an as an example,the internal,external and comprehensive accessibility of the completed orbital sites in Xi'an was calculated.Then,the track sitesare divided into four types: Outward-oriented,Inward-oriented,Transitional and Balanced sites.Then,this paper proposed to improve the accessibility of Inward-oriented sites by improving the construction level of traffic infrastructure in the radiation range of the site,and improve the accessibility level of the Outward-oriented sites by shortening the waiting time/transfer time and increasing the speed of the vehicles.For transitional sites,the Outward-oriented site optimization strategy optimizes the track site,so as to propose targeted optimization strategies for each type of site.